Finger actuated fluid pump dispensers are adapted to be secured to containers which are filled with fluids and which can be manually operated to dispense such fluids. Such dispensers typically have actuators which are normally in raised position and which are manually depressed by finger actuation to initiate a discharge of a quantity of fluid from a container. When the manual pressure is removed, the actuators are automatically returned to the normal raised position.
For typical non-pharmaceutical uses such as dispensing of hair sprays or deodorants, a general purpose finger actuated fluid pump dispenser employs a dispensing system wherein the dispensing pressure depends upon the speed and duration of finger actuation and wherein the amount of fluid dispensed, known as the dosage is not regulated or metered accurately. The dosage will necessarily vary from time to time as the dispenser is used, because the variation in dispensing stroke can cause variations in dosage.
While dosage variation is not of great concern in most applications, control of dosage is of great concern in pharmaceutical applications where dosages must be accurately metered and cannot be varied because of variations in dispensing stroke. Accordingly, finger actuated fluid pump dispensers for pharamaceutical employ dispensing systems wherein dispensing pressure is properly controlled regardless of variations in the speed of finger actuation.
However, known finger actuated pump dispensers for pharmaceutical will only deliver accurately metered dosages when a specified method of actuation is employed. For example, the user must complete an actuation stroke. If the user interrupts the actuation stroke, the dosage will vary depending upon the method of such interruption.
The present invention is directed toward a finger actuated pump dispenser for pharmaceutical applications which not only discharges fluid at a predetermined pressure but also delivers a predetermined dosage regardless of the method of actuation employed.